Yes, Fleabane is toxic to dogs!
Dogs accidentally consuming the Fleabane plants can show the following clinical symptoms: Vomiting, Prolonged Depression, Incoordination, Hypersalivaton, Sleepiness Or Excitation, Dilated Pupils, Low Body Temperature, Low Blood Pressure, Coma, Seizure And Death (In Rare Cases).
Fleabane consumption is also toxic to Cats and Horses.
Toxic Principles Of Fleabane: Irritant.
More Info About The Fleabane Plant
Scientific Name: Erigeron speciosus
Family: Asteraceae.
Also known as: Showy Daisy, Horseweed, Seaside Daisy.
The answer is based on information found on The American Society for the Prevention of Cruelty to Animals (ASPCA) website.